Method and apparatus for improved tread splicing

ABSTRACT

A mold for molding a tire tread comprises a plurality of mold segments. Each of the plurality of mold segments includes an integer number of tread pitch repetitions. The plurality of mold segments are structured to be coupled to each other end-to-end so as to form the mold such that the mold includes an integer number of tread pitches. The mold also includes at least one mold end segment positioned on at least one end of the mold and has a mold end segment length shorter than a length of each of the plurality of mold segments.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims to priority to U.S. Provisional PatentApplication No. 62/166,286, filed May 26, 2015 and entitled “Method andApparatus for Improved Tread Splicing”, the entire disclosure of whichis incorporated herein by reference.

FIELD

Some embodiments described herein relate generally to apparatus andmethod of splicing a plurality of tire treads.

BACKGROUND

Retreaded tires provide an economical way to gain additional use fromtire casings after the original tread or retread has become worn.According to some methods of retreading, sometimes referred to as coldprocess retreading, worn tire tread on a used tire is removed to createa buffed, generally smooth treadless surface about the circumference ofthe tire casing to which a new layer of tread may be bonded.

The tire casing may be inspected for injuries, some of which may beskived and filled with a repair gum while others may be severe enough towarrant rejection of the casing. After completion of the skivingprocess, the buffed surface may be sprayed with a tire cement thatprovides a tacky surface for application of bonding material and newtread. Next, a layer of cushion gum may be applied to the back, i.e.,the inside surface of a new layer of tread, or alternatively, the layerof cushion gum may be applied directly to the tacky surface on the tirecasing. Conventionally, the cushion gum is a layer of uncured rubbermaterial. The cushion gum and tread may be applied in combination aboutthe circumference of the tire casing to create a retreaded tire assemblyfor curing. Alternatively, a length of tire tread may be wrapped aroundthe tire casing with the cushion gum already applied. The cushion gummay form the bond between the tread and the tire casing during curing.

Following assembly of the tire casing, cement, cushion gum and tread,the overall retreaded tire assembly may be placed within a flexiblerubber envelope. An airtight seal may be created between the envelopeand the bead of the tire. The entire envelope tire assembly may beplaced within a curing chamber and subjected to a vulcanization processthat binds the materials together.

Portions of the above-described method of cold process retreading may beaccomplished on a tire builder. Tire builders may include spindles onwhich a tire and a roll of cushion gum may be mounted. In such tirebuilders, the cushion gum may be dispensed by hand as the tire isrotated to adhere the cushion gum to the tire casing. After the cushiongum has been applied, the circumference of the tire casing with cushiongum may be measured and an applicable length of tread may be cut.

In such tire building systems, a length of tread may be applied to thecushion gum and casing. Variability in the cut length of the tire treadmay demand manipulation of the tread segment around the perimeter of thetire casing and cushion gum to create an appropriately located splice inwhich both ends of the tread length abut one another. It is oftendesirable, for aesthetic and performance purposes, to match the tiretread design at each end of the tire tread length so that where the twoends of the tire tread length match at the splice, the repetitivepattern of the tire tread design is substantially continuous. Thecomplication and difficulty of such procedures may be increased becausethe tread patterns are subject to varying characteristics depending onthe cut location. For instance, from a cross-sectional perspective, thetread end surfaces may have varying total surface area quotients,varying amounts of surface area farther from the center of rotation ofthe tire and closer to the contact surfaces, etc. In the bondingprocess, such parameters of the multi-dimensional profile of the treadsplice may provide for improved operation in the vulcanization process,particularly in relation to use of envelopes and pressure.

Various devices and methods for cutting a tread length to an appropriatesize and location have been proposed in the past. For example, U.S. Pat.No. 6,899,778 (the '778 patent), the contents of which are incorporatedherein in their entirety by reference, generally describes a tirebuilder. The machine may include a rotatable hub for mounting of abuffed tire casing and a cushion gum applicator that may be configuredto stretch a length of cushion gum onto a tire casing. A tread dispensermay automatically dispense a length of tire tread based on thecircumference of the tire casing or the circumference of the tire casingplus the cushion gum. Thereafter, a tread applicator of the machine maymanipulate the length of tire tread onto the cushion gum to accommodatevariability in measurements, cutting, etc.

Machines such as described in the '778 patent may rely on semi-automaticor automatic processes when determining what length of tread isappropriate for a particular casing. Such processes may includemeasurements providing information indicative of the circumference ofthe casing as well as the length of tread that is dispensed from a roll.When an approximate length of tread has been dispensed to match themeasured circumference of the casing, a manual cutting operation may beemployed to sever a length of tread.

Variability in the measurements of the circumference of the casing or ofthe dispensed length of tread may result in dimensional variations whencutting the length of tread. Manual intervention in the cutting processof the length of tread to provide a substantially uninterrupted treadpattern around the entire periphery of the retreaded tire may beinaccurate as well as compound the dimensional variability indetermining the appropriate length of tread that is required. Suchintervention may often fail to account for the characteristics of thecross-sectional tread and improving the characteristics of the abuttingends of the tread for performance and bonding characteristics. Theinaccuracy of the manual cutting operation in matching the tread patternmay adversely affect the service life and aesthetic appeal of the finalretreaded tire. In certain instances, the compounded variability incutting the appropriate length of tread may make the length of treadunsuitable for use on a retreaded tire, thus necessitating the cuttingof an additional length. Such rework operations are time consuming,increase the cost of the retreading operation, increase waste, and soforth.

BRIEF SUMMARY

Some embodiments relate to methods and apparatuses for making retreadedtires and, more particularly, to apparatuses and methods in which aleading edge or trailing edge of a roll of preformed treads may be cutat a location relative to the tread pattern to provide for improvedsplicing while providing a durable splice across varying retreadingconditions and reducing scrap in the retreading process.

In some embodiments, a mold for molding a tire tread may include aplurality of mold segments. Each of the plurality of mold segments mayinclude an integer number of tread pitch repetitions. The plurality ofmold segments may be structured to be coupled to each other end-to-endso as to form the mold such that the mold may include an integer numberof tread pitches. The mold also includes at least one mold end segmentpositioned on at least one end of the mold and has a mold end segmentlength shorter than a length of each of the plurality of mold segments.

In some embodiments, a curing press for forming a tire tread may includea top press block, a bottom press block and at least one mold assemblypositioned between the top press block and the bottom press block. Theat least one mold assembly may include a platen and a mold. The mold mayinclude a plurality of mold segments. Each of the plurality of moldsegments may include an integer number of tread pitch repetitions. Theplurality of mold segments may be structured to be coupled to each otherend-to-end so as to form the mold such that the mold may include aninteger number of tread pitches. The mold also includes at least onemold end segment positioned on at least one end of the mold and has amold end segment length shorter than a length of each of the pluralityof mold segments.

In some embodiments, a method of forming a tire tread may includeassembling a plurality of mold segments end-to-end so as to form anelongate structure. An end segment piece may be added to a first end ofthe elongate structure. The plurality of mold segments and the endsegment piece may be attached so as to form a unitary mold. The mold maybe used in a pressing operation to form a tire tread.

All combinations of the foregoing concepts and additional conceptsdiscussed in greater detail below (provided such concepts are notmutually inconsistent) are contemplated as being included within thisdisclosure. In particular, all combinations of claimed subject matterappearing at the end of this disclosure are contemplated as beingincluded within this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features will become more fully apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings.

FIG. 1 is a partial view of a curing press in accordance with anembodiment.

FIG. 2 is an outline view of a curing mold in accordance with anembodiment.

FIG. 3 is a cross section of a curing mold and a finished tread inaccordance with an embodiment.

FIG. 4 is a segmented mold tray in accordance with the disclosure.

FIG. 5 is a mold end-piece in accordance with the disclosure.

FIG. 6 is a middle piece for a mold in accordance with the disclosure.

FIG. 7 is a mold end-piece in accordance with the disclosure.

FIG. 8 is a segmented mold tray in accordance with the disclosure.

FIG. 9 is a pre-cured tread strip in accordance with the disclosure.

FIG. 10 is a partial, enlarged view of a mold end-piece in accordancewith the disclosure.

FIG. 11 is a detail view of an end-mark in accordance with thedisclosure.

FIG. 12 is a flowchart for a method of assembling a mold in accordancewith the disclosure.

Reference is made to the accompanying drawings throughout the followingdetailed description. In the drawings, similar symbols typicallyidentify similar components, unless context dictates otherwise. Theillustrative implementations described in the detailed description,drawings, and claims are not meant to be limiting. Other implementationsmay be utilized, and other changes may be made, without departing fromthe spirit or scope of the disclosure. It will be readily understoodthat the aspects of the present disclosure, as generally describedherein, and illustrated in the figures, can be arranged, substituted,combined, and designed in a wide variety of different configurations,all of which are explicitly contemplated and made part of thisdisclosure.

DETAILED DESCRIPTION

Some embodiments relate to methods and apparatuses for making retreadedtires and, more particularly, to an apparatus and method in whichpreformed treads may be consistently cut in a location relative to thetread pattern that provide for improved splicing while providing adurable splice across varying retreading conditions and reducing scrapin the retreading process.

A curing press 100 from a side perspective is partially shown in FIG. 1.The curing press 100 may be part of a larger tread forming operationthat includes, for example, a composite preform building apparatus, aforming press, and other structures (not pictured). The curing press 100may include top press blocks 102 and bottom press blocks 104. Betweenthe top press blocks 102 and the bottom press blocks 104 are positioneda plurality of mold assemblies 106 that each include two parts that cometogether to define an internal molding cavity. In the illustration ofFIG. 1, a mold 108 and a platen 110 make up the mold assembly 106, butother configurations may be used. For example, what is referred torelative to FIG. 1 as a mold 108 may be positioned in an invertedorientation in the curing press 100 such that a mold cavity 112 isfacing down. In such an embodiment, the platen 110 would be positionedbelow the mold 108 such that it fits over the mold cavity 112. In thedescription that follows, a particular orientation having the mold 108located beneath the platen 110 is discussed for illustration, but itshould be appreciated that the relative orientation of these twoelements may be in other orientations. Moreover, although six moldassemblies 106 are shown, a single assembly or a different number ofmold assemblies may be used. Each mold 108 forms a mold cavity 112 intowhich a preform may be packed or loaded. Following the application ofpressure and heat to the closed mold assembly 106, a vulcanized tread114 can emerge. In other alternatives, the press may be configured toprovide continuous manufacture of the molded article or a tread in beltor other form.

The curing press 100 further includes linkages 116 that connect theparts of each mold assembly 106 to frame members or posts 118, whichinclude mechanisms (not shown) that can selectively move the variousparts of each mold assembly 106 vertically to enable the loading ofpreforms and the unloading of finished treads from each mold assembly106. In a forming process for a tread 114, a tread preform, which may bebuilt by successively stacking layers of rubber with other materialssuch as thread, fabric, steel belts, wire mesh and the like, is loadedinto a mold 108. Each mold 108 may have ridges and depressions formedtherein structured to shape and mold the lugs and sipes of a desiredpattern in the emerging tread 114. The platen 110 may be placed in anopposed relationship to the mold cavity 112 and a curing process mayensue that vulcanizes the preform into the tread 114. The tread maythereafter be detached and removed from the mold 108.

When forming the tread 114, the mold 108 imprints onto the preform apredetermined pattern of lugs and/or ribs. In reference to FIG. 2, theselugs may be formed as depressions 202 in a bottom surface 204 of themold 108, which may be separated by sipe blades or ridges 203. The mold108 may form an internal cavity 206 that is open from the top andsurrounded by the bottom surface 204 and walls 210 that extend aroundthe perimeter of the cavity 206. Although a mold 108 configured to forma single tread strip is shown, the mold 108 may include two or moreadditional cavities extending parallel to one another and configured toform two or more tread strips from a single preform. In the illustratedembodiment, the single-cavity mold 108 has a generally elongaterectangular shape that extends along an axis 212. The mold 108 mayfurther include two tracks or ledges 214 extending along its sides,generally parallel to the axis 212. Each ledge 214 may be disposed on aside of the mold 108 and may include a track 216 that extends generallyparallel to a top edge 218 of the side portion of the wall 210 at anoffset vertical distance 220 therefrom. Although the ledges 214 areshown to have a length that is about equal to the overall length of themold 108 in FIG. 2, the ledges 214 can extend past the ends of the mold108, as shown in FIG. 1.

A cross section of the mold assembly 106 during a molding operationphase is shown in FIG. 3. In this illustration, the mold assembly 106 isshown opened following a molding and curing operation for the tread 114.The top mold or platen 110 may include a bottom surface 222 that formsthe top or inner surface 224 of the tread 114. The lateral surfaces 226and the outer or tread surface 228 of the tread 114 are formed,respectively, by the side walls 210 and bottom surface 204 of the mold108. Flash 227 may remain on the tread 114 along the interface betweenthe platen 110 and the mold 108. A plurality of lugs 230 may be arrangedalong the tread surface 228 and are formed by the corresponding lugdepressions 202.

As may be seen in the cross section of FIG. 3, certain tread patternsmay include small or even negative draft angles formed in the surfacesaround the sides of the lugs 230. Draft angle denotes the resultingangle formed by mold surfaces relative to the direction of removal ofthe molded article from the mold. Accordingly, positive draft angles aredisposed such that the removal of the molded article is facilitated,whereas negative draft angles are disposed such that at least somedeformation of the molded article is required to remove it from themold. In the cross section of FIG. 3, the lugs 230 may have negativedraft angles on their side surfaces 232, which have been exaggerated forthe sake of illustration. As can be appreciated, certain portions of thelugs may have to elastically deform when removing the tread 114 from themold 108.

In one embodiment in accordance with the disclosure, the mold 108 may bemade by assembling a plurality of mold segments 300, as shown in FIG. 4.Each segment 300 may extend over a predetermined length, l, such thatthe total length of the mold 108, L, which may be made up from n moldsegments 300 can be calculated as L=n*l. It should be appreciated thatthe mold segments 300 are either directly connected to one another orcan be, alternatively, placed on an elongate tray (not shown), forexample a mold tray, and secured thereon, threaded on an elongate beam(not shown), or the like, to form the mold 108. In the illustratedembodiment, each of the mold segments 300 includes a whole number or,stated differently, an integer number of tread pitch repetitions, whichmay be cut in locations within the tread pitch but which, when the moldsegment is viewed in its entirety, form an integer number of treadpitches. For example, each of the mold segments 300 shown in FIG. 4forms two whole tread pitches. In this way, when the mold segments 300are assembled together into the mold 108, the mold 108 includes aninteger number of tread pitches. It is noted that the pitch spacing maychange or be varied along the length of the mold 108 for noiseattenuation reasons, but the number of pitches per mold segments may bemaintained at a whole number at more or fewer than the two that areshown here.

In reference now to FIG. 6, each mold segment 300 may include a bodyportion 302 into which various depressions 304 may be formed. Thedepressions 304 imprint onto a preform to form the various features ofthe tread 114, as described above. In the illustrated embodiment, eachsegment 300 may form two complete sets of lugs or, stated differently,two complete tread pitches. Selecting an appropriate length for eachmold segment 300 may depend on a number of factors including the lengthof the final tread 114, desired variations in pitch length along thetread band, if any, size of the tread, and others. For example, the moldsegments 300 may range in length between 1 and 6 inches (about 2.5 to 15cm), but other lengths may be used. Other design options for selecting adesirable tread section may include avoiding creating thin featuresbetween the segments, which may not form properly, preferring featuresthat allow proper alignment of the segments, for example, to avoidplacing the segments backwards in the mold, and other features aimed atoptimizing the design and structure of the mold segments of the moldassembly.

In some instances, the tread rolls resulting from a tire tread moldingoperation may be cut at an end of the roll, for example to removecontamination and to present a maximum surface area that may be suitablefor splicing two cut ends of the roll around a tire carcass during aretreading process. In some instances, the initial cut may removeseveral inches of the tread, because, for example, the mold segmentinterfaces and, specifically, the leading end or trailing end of theroll formed by the last mold segment used to make the mold, may not beoptimized for presenting a location of an end cut to the roll for asuitable or desirable face for tread splicing. That is, because treadrolls and/or tire treads may be damaged during transport and/or havecontamination on an initial or final end, a tread portion may need to beremoved to eliminate the damage and/or contamination and to produce atire tread cut-end conducive to splicing. Thus, the rather lengthyinitial cut from each tread roll may generate increased waste materialand cost for tire re-treading operators. By providing a modified initialand/or end segment different from the mold segments 300, the amount oftread portion to be removed to produce a suitable or desirable face fortread splicing may be reduced.

In some embodiments, the leading edge of a pre-cured tread roll, e.g.,either or both ends of the tread 114, may be optimized to reduce waste,such as by allowing a shorter cut to be made. In some embodiments, thelength of tread that may be cut during an initial cut of a new roll thatmay be minimized by adjusting a mold end segment, such as the mold endsegment 308 of FIG. 5 or the mold end segment 306 of FIG. 7, to resultin a tread end requiring a smaller or reduced section of tread to beremoved. For illustration, where previous designs that utilize only thesame mold segments 300 may have necessitated a tread length of severalinches to be removed to permit removal of the contamination and/ordamage while also providing a suitable face for tread splicing,providing one or more modified mold end-segments 306, 308 in accordancewith the present disclosure provides for removal of a smaller portion ofthe end of the tire tread and/or roll to produce a tire tread cut-endconducive to splicing while also reducing the amount of removed tiretread. For instance, the reduced portion of tread removed may be reducedfrom several inches to a length of tread on the order of 0.125 to 0.25inches. In the illustrated embodiment of FIG. 6, about 0.5 inches may beremoved from the mold segment 300 to create the mold end-segment 308and/or the mold end-segment 306. Further, the tread end presented by themold end-segment 306, 308 in accordance with the present disclosure mayform a tread having a leading tread edge that is conducive to splicingwhile permitting a reduced portion of the tire tread and/or roll to beremoved to account for any damage and/or contamination. Relative to thepresent disclosure, a tread cross section that is conducive to splicingmay be one that can fulfill any number of factors and performanceattributes including a maximization of contact area on the leading faceof the cut tread that may mate with a corresponding face on the oppositeside of the tread during a splice operation as the tread is wrapped andsecured around a tire carcass that is being retreaded. In someembodiments, the mold end-segment may be have a modified shape orinclude features conducive to splicing in addition to in addition to, orinstead of being shorter in length to the mold segments 300. Forexample, the mold end-segment may be cut in a particular pattern (e.g.,a zig-zag pattern, a jagged pattern, have an under or over cut, etc.)structured to mate with a corresponding pattern on the opposite end ofthe tread so as to facilitate splicing.

In the illustrated embodiment of FIG. 6, the mold segment 300 mayinclude one or two areas that can be removed to create end-segmentshaving the characteristics described herein, i.e., end-segments having alength that may have been optimized to create a favorable or desirabletread strip having end-features that are conducive to reducing wastewhile providing ends that are suitable for tread splicing after removinga portion of the tread end without removing excessive material. Two suchareas are shown on the mold segment 300 in FIG. 6 and are denoted byrectangular areas A and B. Specifically, a mold segment 300 may bemodified to create a first end-segment 306, as shown in FIG. 7, byremoving material from the body portion along rectangle A, and a secondend-segment 308 may be formed, as shown in FIG. 5, by removing materialfrom the body portion along rectangle B. It is noted that each of therectangles A and B encompasses about ½ of a tread pitch such that bothend-segments together remove about a full tread pitch.

When assembling a mold, for example, the mold 108 (FIG. 2), a number ofmold segments 300 may be strung along a single row such that theymatingly engage one another. The number of segments that may be useddepends on the length of each segment and the desired length of thetread being formed, which may suffice for retreading two or more tires.At either end of the string of mold segments 300 used to create themold, an end-segment 306 or 308 may be placed. Such an arrangement isshown in FIG. 8, where a plurality of mold segments 300 are arranged ina row along a middle portion of a mold construction, and where a firstend-segment 306 is placed at one end of the mold set. As shown, a secondend-segment 308 is placed on an opposite end of the set of moldsections. The second end-segment is optional.

Referring now again to FIGS. 5-7, the rectangular area A, which may beremoved to form the first end-segment 306 (FIG. 7), may intersect thebody portion of the regular mold segments 300 along a line, A1, whichextends perpendicularly relative to a long dimension of the mold segment300 in a direction of the tread. The line A1 extends through portions ofthe outer and inner lugs of the tread that are proximate to areas of thetread pattern having a maximum cross section, which may be removedbefore use to provide a cut end of the tread that may be conducive tosplicing. To identify the line A1, along which the initial cut is made,cut-marks 402 may be etched into the mold segments 300 at appropriatespots. Enlarged views of the cut marks 402 are shown in FIGS. 10 and 11.

In reference to FIG. 10, an enlarged portion of an end-segment 306 isshown. The end-mold or first end-segment 306 may form a depression 404that develops a lug 230 (FIG. 3) in the finished tread. The depression404 may be closed on one end to contain the formed tread as thedepression 404 may be disposed at one end of the tread. Walls 406 maysurround the depression 404 so as to form the channels between the lugs,and shorter walls 408 may form depressions within the respective lug.The cut-mark 402 may be formed in a bottom wall of the depression 404,such that it may create a corresponding tread cut-mark on a bottom ofthe resulting tread that protrudes outwardly from a tread plane. Thecut-mark 402 may take on any appropriate shape that denotes a desiredtread end-cut location in the finished tread. For example, as shown inthe enlarged detail of FIG. 11, the cut-mark may include a circle 410that is bifurcated by a line 412 extending diametrically across thecircle 410. End portions 414 of the line 412 may extend past the end ofthe circle 410 such that the entire cut-mark 402 has a shape resemblingthe capital Greek letter “phi” (Ø). During use, the resulting tread maybe cut along the line 412 to expose a first end of the tread. Thediameter of the circle 410 is also configured to represent an acceptablecutting region along which the tread may be cut. As an also be seen fromFIG. 10, additional marks 416 and 418 may be included in the finishedtread that denote possible cut locations, as is more fully described inU.S. Pat. No. 8,820,375, which is incorporated herein by reference init's entirety.

In general, a typical retreading process or operation involves buffingan existing tread from a tire to form a carcass, applying a cushion gumof uncured rubber around the buffed carcass to act as a glue, wrapping astrip of pre-cured tread around the gum, stitching the ends of the treadtogether, and then heat-treating the assembly to produce a tire. Theseoperations may be automatic, manual, or semi-automatic, and may furtherinclude placing cushion gum between the faces being stitched together.

In one aspect, therefore, the present disclosure is directed to a treadthat is made from a mold having a plurality of mold segments that makeup a central portion of the mold, and having a different mold sectionmaking up at least one end of the mold, i.e., having a differentend-segment. Such a tread 400 is shown if FIG. 9. It is noted that alength, L, of the tread 400 may correspond to the length, L, of the mold108 used to make the tread 400 (see FIG. 4), less some fraction of or afull tread pitch due to the use of end-segments, for example,end-segments 306 and 308 (see FIGS. 5 and 7) that may be used toassemble the mold. When both end-segments are used to remove about afull thread pitch, waste in using the tread 400 is further reduced. Thetread 400 includes cut-marks 402 on either end. In some embodiments,only one side may be used to cut the tread 400.

A flowchart for a method 500 of assembling a mold in accordance with thedisclosure is shown in FIG. 12. The method 500 includes assembling aplurality of mold segments end-to-end to form an elongate structure at504, which elongate structure constitutes an elongate mold into which atread strip may be formed. As discussed above, the total length of themold will depend on the total length of the various mold segments thatare assembled end to end. Moreover, even though the various moldsegments can have different individual lengths, the tread pitch countincluded in each mold section will be the same as the remaining moldsegments.

An end-segment piece may be added to an end of the elongate structure at506 as a termination piece to complete one end of the mold. Theend-segment may have shorter length and/or a different number of pitchcount than each of the mold segments that make up the middle portion ofthe mold. Optionally, a second end-segment may be added to the other endof the elongate mold structure at 508. In some embodiments, theplurality of mold segments and the end segment piece may be positionedon a mold tray. The plurality of mold segments and the end segment piecemay be secured to the mold tray.

The various mold sections including the first end-segment piece and,optionally, the second end-segment piece, may be releasably orpermanently attached together at 510 so as to form a unitary mold. Theattachment between the various mold pieces may be accomplished directly,for example, by connecting one mold segment to its adjacent segments inthe elongate structure, or indirectly, for example, by attaching eachmold piece to a holder, rail or other structure that holds the varioussegments together. Moreover, connection of the mold segments can bereleasable or breakable, for example, by using fasteners, or permanent,for example, by welding the various segments together or to thesupporting structure. The mold may then be used in a pressing operationto form a tire tread at 512.

In some embodiments, a portion of at least one end of the tire tread iscut at 514 so as to form a cut-end thereof. For example, the at leastone end of the tire tread may be cut proximate to a tread cut-markdefined on the tire tread, as described herein. The cut tire tread maybe positioned around a tire at 516, for example positioned around anouter circumference of a buffed tire. An adhesive such as curing gum orany other adhesive may be disposed on the outer circumference so as tocause the tire tread to adhere to the outer circumference of the buffedtire.

The cut-end of the tire tread may be spliced with an opposite end of thetire tread at 518. For example, the cut-end of the tire tread may befused or stitched together with the opposite end of the tire tread. Thetread pattern at the cut-end of the tire tread may substantially alignwith the tread patter on the opposite end of the tire tread. The tiretread and the tire may be cured at 520 so as to form a retreaded tire.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas being absolute on a scale but should only indicate relativeimprovement, nothing should be construed as indicating any non-claimedelement as essential to the practice of the invention.

It should be noted that the term “example” as used herein to describesome embodiments is intended to indicate that some embodiments arepossible examples, representations, and/or illustrations of possibleembodiments (and such term is not intended to connote that someembodiments are necessarily extraordinary or superlative examples).

The terms “coupled,” “connected,” and the like as used herein mean thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent) or movable (e.g., removableor releasable). Such joining may be achieved with the two members or thetwo members and any additional intermediate members being integrallyformed as a single unitary body with one another or with the two membersor the two members and any additional intermediate members beingattached to one another.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of thisdisclosure or of what may be claimed, but rather as descriptions offeatures specific to particular implementations. Certain featuresdescribed in this specification in the context of separateimplementations can also be implemented in combination in a singleimplementation. Conversely, various features described in the context ofa single implementation can also be implemented in multipleimplementations separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

1. A mold for molding a tire tread, comprising: a plurality of moldsegments, each of the plurality of mold segments including an integernumber of tread pitch repetitions, the plurality of mold segmentsstructured to be coupled to each other end-to-end so as to form the moldsuch that the mold includes an integer number of tread pitches; and atleast one mold end segment structured to be positioned on at least oneend of the mold, the mold end segment having a mold end segment lengthshorter than a length of each of the plurality of mold segments.
 2. Themold of claim 1, further comprising: a mold tray, wherein the pluralitymold of segments and the at least one mold end segment are positioned onthe mold tray and secured thereto.
 3. The mold of claim 1, wherein eachof the plurality of mold segment forms two whole tread pitches.
 4. Themold of claim 1, wherein a length of the each of the plurality of moldsegments is in a range of 1 inch to 6 inches.
 5. The mold of claim 4,wherein a length of the at least one mold end segment is equal to orless than 0.5 inches.
 6. The mold of claim 1, wherein the at least onemold end segment comprises a cut-mark defined thereon, the cut-markstructured to produce a corresponding tread cut-mark on the tire treadmolded thereon, the tread cut-mark indicating the portion of the treadstructured to be cut off so as to make the end of the tire treadconducive to splicing.
 7. The mold of claim 6, wherein the cut-markcomprises a circle bifurcated by a line extending diametricallythereacross.
 8. A curing press for forming a tire tread, comprising: atop press block; a bottom press block; at least one mold assemblybetween the top press block and the bottom press block, the at least onemold assembly comprising; a platen, and a mold, comprising: a pluralityof mold segments, each of the plurality of mold segments including aninteger number of tread pitch repetitions, the plurality of moldsegments structured to be coupled to each other end-to-end so as to formthe mold such that the mold includes an integer number of tread pitches;and at least one mold end segment structured to be positioned on atleast one end of the mold, the mold end segment having a mold endsegment length shorter than a length of each of the plurality of moldsegments.
 9. The curing press of claim 8, wherein the mold includestracks extending along its sides parallel to a longitudinal axis of themold.
 10. The curing press of claim 8, wherein the at least one moldassembly further comprises: a mold tray, wherein the plurality of moldsegments are positioned on the mold tray and secured thereto.
 11. Thecuring press of claim 8, wherein each of the plurality of mold segmentforms two whole tread pitches.
 12. The curing press of claim 8, whereina length of the each of the plurality of mold segments is in a range of1-6 inches.
 13. The curing press of claim 12, wherein a length of the atleast one mold end segment is equal to or less than 0.5 inches.
 14. Thecuring press of claim 13, wherein the at least one mold end segmentincludes a cut-mark defined therein, the cut-mark structured to producea corresponding tread cut-mark on the tire tread molded thereon, thetread cut-mark thereby indicating the portion of the tread which may becut off so as to make the end of the tire tread conducive to splicing.15. The curing press of claim 14, wherein the cut-mark comprises acircle bifurcated by a line extending diametrically thereacross.
 16. Amethod of forming a tire tread, comprising: assembling a plurality ofmold segments end-to-end so as to form an elongate structure; adding anend segment piece to a first end of the elongate structure; attachingthe plurality of mold segments and the end segment piece so as to form aunitary mold; and using the unitary mold in a pressing operation to forma tire tread.
 17. The method of claim 16, further comprising: adding asecond end segment to a second end of the elongate structure oppositethe first end.
 18. The method of claim 16, further comprising:positioning the plurality of mold segments and the end segment piece ona mold tray; and securing the plurality of mold segments and the endsegment piece to the mold tray.
 19. The method of claim 16, furthercomprising: cutting a portion of at least one end of the tire tread soas to form a cut-end of the tire tread; positioning the tire treadaround a tire; and splicing the cut end of the tire tread with anopposite end of the tire tread; and curing the tire tread and the tireso as to form a retreaded tire.
 20. The method of claim 19, wherein thecutting removes half of a tread pitch from the at least one end of thetire.